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Advanced ceramic sponge materials with temperature-invariant high compressibility are urgently needed as thermal insulators, energy absorbers, catalyst carriers, and high temperature air filters. However, the application of ceramic sponge materials is severely limited due to their complex preparation process. Here, we present a facile method for large-scale fabrication of highly compressible, temperature resistant SiO 2 -Al 2 O 3 composite ceramic sponges by blow spinning and subsequent calcination. We successfully produce anisotropic lamellar ceramic sponges with numerous stacked microfiber layers and density as low as 10 mg cm −3 . The anisotropic lamellar ceramic sponges exhibit high compression fatigue resistance, strain-independent zero Poisson’s ratio, robust fire resistance, temperature-invariant compression resilience from −196 to 1000 °C, and excellent thermal insulation with a thermal conductivity as low as 0.034 W m −1 K −1 . In addition, the lamellar structure also endows the ceramic sponges with excellent sound absorption properties, representing a promising alternative to existing thermal insulation and acoustic absorption materials. Temperature-invariant highly compressible ceramic sponges are attractive for thermal insulators and energy absorbers, but development is limited by complex preparation processes. Here the authors report large-scale fabrication of silica-alumina composite ceramic sponges via blow spinning and calcination.

PurposeThrough the lens of affective events theory, this study sought to investigate the associations of individual-focused transformational leadership, namely individualized consideration and intellectual stimulation, with employee strengths use (ESU) and the mediating role of positive affect and the moderating role of core self-evaluation (CSE) in these associations.Design/methodology/approachThe authors collected data by a three-wave research design. Hypotheses were examined with a sample of 178 employees working in various organizations in China.FindingsThe results revealed that both individualized consideration and intellectual stimulation have positive relationships with ESU and positive affect partially mediates these two relationships. Contrary to our hypotheses, CSE negatively moderated the relationship of intellectual stimulation with positive affect and the mediational effect of positive affect on the relationship between intellectual stimulation and ESU. However, CSE did not moderate the relationships between individualized consideration, positive affect and ESU.Originality/valueThis study was the first to empirically examine the relationships of individualized consideration and intellectual stimulation with ESU and the mediating effect of positive affect and the moderating effect of CSE on these relationships.

We describe pLink 2, a search engine with higher speed and reliability for proteome-scale identification of cross-linked peptides. With a two-stage open search strategy facilitated by fragment indexing, pLink 2 is ~40 times faster than pLink 1 and 3~10 times faster than Kojak. Furthermore, using simulated datasets, synthetic datasets, 15 N metabolically labeled datasets, and entrapment databases, four analysis methods were designed to evaluate the credibility of ten state-of-the-art search engines. This systematic evaluation shows that pLink 2 outperforms these methods in precision and sensitivity, especially at proteome scales. Lastly, re-analysis of four published proteome-scale cross-linking datasets with pLink 2 required only a fraction of the time used by pLink 1, with up to 27% more cross-linked residue pairs identified. pLink 2 is therefore an efficient and reliable tool for cross-linking mass spectrometry analysis, and the systematic evaluation methods described here will be useful for future software development. The identification of cross-linked peptides at a proteome scale for interactome analyses represents a complex challenge. Here the authors report an efficient and reliable search engine pLink 2 for proteome-scale cross-linking mass spectrometry analyses, and demonstrate how to systematically evaluate the credibility of search engines.

Autophagy is a primarily degradative pathway that takes place in all eukaryotic cells. It is used for recycling cytoplasm to generate macromolecular building blocks and energy under stress conditions, to remove superfluous and damaged organelles to adapt to changing nutrient conditions and to maintain cellular homeostasis. In addition, autophagy plays a critical role in cytoprotection by preventing the accumulation of toxic proteins and through its action in various aspects of immunity including the elimination of invasive microbes and its participation in antigen presentation. The most prevalent form of autophagy is macroautophagy, and during this process, the cell forms a double-membrane sequestering compartment termed the phagophore, which matures into an autophagosome. Following delivery to the vacuole or lysosome, the cargo is degraded and the resulting macromolecules are released back into the cytosol for reuse. The past two decades have resulted in a tremendous increase with regard to the molecular studies of autophagy being carried out in yeast and other eukaryotes. Part of the surge in interest in this topic is due to the connection of autophagy with a wide range of human pathophysiologies including cancer, myopathies, diabetes and neurodegenerative disease. However, there are still many aspects of autophagy that remain unclear, including the process of phagophore formation, the regulatory mechanisms that control its induction and the function of most of the autophagy-related proteins. In this review, we focus on macroautophagy, briefly describing the discovery of this process in mammalian cells, discussing the current views concerning the donor membrane that forms the phagophore, and characterizing the autophagy machinery including the available structural information.

We theoretically investigate the third-order nonlinear Hall effect by employing the quantum kinetic equation and present an analytic formula for the third-order harmonic conductivity, where the intraband and the mixed inter-band contributions caused by the external electric field as well as the multiphoton process dressed Berry curvature are unveiled. These results are applied in a two-dimensional Dirac system. We find that the third-order harmonic conductivity exhibits a crossover from the negative to positive value due to the intraband transition of the electrons in the low-frequency region, whereas a kink or dip structure due to the multiphoton process between the conduction and valence bands in the high-frequency region. In experiment, these features can be identified by detecting the transverse current. Our work deepens the understanding of the multiphoton process in the nonlinear transport of topological materials and enlightens a possible way to its characterization in experiments.

PurposeThe aim of the present study was to examine the association of subordinate-oriented strengths-based leadership (SSBL) with subordinates’ job performance (task performance and innovative behavior) as well as the meditating role of supervisor–subordinate guanxi (SSG) in these relationships.Design/methodology/approachSelf-report data on SSBL, SSG, task performance and innovative behavior were gathered from 642 Chinese employees working in various Chinese enterprises. Structural equation modeling was used to analyze the data.FindingsThe results indicated that SSBL is positively related to subordinates’ job performance (task performance and innovative behavior). Furthermore, SSG partially mediated the relationship of SSBL with task performance and with innovative behavior.Originality/valueThis study is the first to empirically examine the relationship of SSBL with job performance. In addition, this study adds to the knowledge on the SSBL–job performance linkage by investigating the mediational effect of SSG on the relationship.

Oxidative-stress-induced apoptosis of granulosa cells is considered to be a main driver of follicular atresia. Increasing evidence suggests a protective effect of melatonin against oxidative damage but the mechanism remains unclear. The aim of this study is to investigate the effects of melatonin on mitophagy and apoptosis of bovine ovarian granulosa cells under oxidative stress, and to clarify the mechanism. Our results indicate that melatonin inhibited H2O2-induced apoptosis and mitochondrial injury of bovine ovarian granulosa cells, as revealed by decreased apoptosis rate, reactive oxygen species (ROS) levels, Ca2+ concentration, and cytochrome C release and increased mitochondrial membrane potential (ΔΨm). Simultaneously, melatonin promoted mitophagy of bovine ovarian granulosa cells through increasing the expression of PTEN-induced putative kinase 1 (PINK1), PARKIN, BECLIN1, and LC3II/LC3I; decreasing the expression of sequestosome 1 (SQSMT1); and promoting mitophagosome and lysosome fusion. After treatment with a mitophagy inhibitor CsA, we found that melatonin alleviated apoptosis and mitochondrial injury through promoting mitophagy in bovine ovarian granulosa cells. Furthermore, melatonin promoted the expression of silent information regulator 1 (SIRT1) and decreased the expression level of forkhead transcription factors class O (type1) (FoxO1). By treatment with an SIRT1 inhibitor EX527 or FoxO1 overexpression, the promotion of melatonin on mitophagy as well as the inhibition on mitochondrial injury and apoptosis were reversed in bovine ovarian granulosa cells. In conclusion, our results suggest that melatonin could promote mitophagy to attenuate oxidative-stress-induced apoptosis and mitochondrial injury of bovine ovarian granulosa cells via the SIRT1/FoxO1 signaling pathway.

PurposeDrawing on conversation of resources theory, the present paper aimed to investigate the effect of strengths-based leadership on follower career satisfaction and the mediating role of follower strengths use as well as the moderating role of emotional exhaustion in the relationship.Design/methodology/approachResearch data were gathered at 3 time points with a sample of 210 participants working in various organizations in China. Structural equation model (SEM) was applied to examine the authors' hypotheses.FindingsThe results indicated that strengths-based leadership has a positive impact on follower career satisfaction and follower strengths use fully mediates the effect of strengths-based leadership on follower career satisfaction. More importantly, emotional exhaustion enhanced the direct relationship between strengths use and career satisfaction and the indirect association of strengths-based leadership with follower career satisfaction through follower strengths use.Research limitations/implicationsThe main limitation of the present paper was the single source of research data.Originality/valueThe present paper advances strengths-based leadership theory and research and provides a new insight into cultivating employee career satisfaction.

Optogenetic methods provide efficient cell-specific modulations, and the ability of simultaneous neural activation and inhibition in the same brain region of freely moving animals is highly desirable. Here we report bidirectional neuronal activity manipulation accomplished by a wireless, dual-color optogenetic probe in synergy with the co-expression of two spectrally distinct opsins (ChrimsonR and stGtACR2) in a rodent model. The flexible probe comprises vertically assembled, thin-film microscale light-emitting diodes with a lateral dimension of 125 × 180 µm 2 , showing colocalized red and blue emissions and enabling chronic in vivo operations with desirable biocompatibilities. Red or blue irradiations deterministically evoke or silence neurons co-expressing the two opsins. The probe interferes with dopaminergic neurons in the ventral tegmental area of mice, increasing or decreasing dopamine levels. Such bidirectional regulations further generate rewarding and aversive behaviors and interrogate social interactions among multiple mice. These technologies create numerous opportunities and implications for brain research. Simultaneous neural activation and inhibition in the same brain region of animals is highly desirable. Here the authors report a wireless, dual-colour optogenetic probe with the co-expression of two spectrally distinct opsins to allow for bidirectional neuronal activity manipulation in a rodent model.

Hydroxide exchange membrane fuel cells offer possibility of adopting platinum-group-metal-free catalysts to negotiate sluggish oxygen reduction reaction. Unfortunately, the ultrafast hydrogen oxidation reaction (HOR) on platinum decreases at least two orders of magnitude by switching the electrolytes from acid to base, causing high platinum-group-metal loadings. Here we show that a nickel-molybdenum nanoalloy with tetragonal MoNi 4 phase can catalyze the HOR efficiently in alkaline electrolytes. The catalyst exhibits a high apparent exchange current density of 3.41 milliamperes per square centimeter and operates very stable, which is 1.4 times higher than that of state-of-the-art Pt/C catalyst. With this catalyst, we further demonstrate the capability to tolerate carbon monoxide poisoning. Marked HOR activity was also observed on similarly designed WNi 4 catalyst. We attribute this remarkable HOR reactivity to an alloy effect that enables optimum adsorption of hydrogen on nickel and hydroxyl on molybdenum (tungsten), which synergistically promotes the Volmer reaction. The lack of efficient and cost-effective catalysts for hydrogen oxidation reaction (HOR) hampers the application of hydroxide exchange membrane fuel cells. Here, authors reported bimetallic MoNi 4 and WNi 4 nanoalloys with marked HOR activity in alkali, among which MoNi4 outperforms the Pt/C catalyst.